This Center for Excellence in Genomic Science will provide two major activities in genomics at the University of Pennsylvania. First, it will bring together investigators with a long-standing commitment to genetics, in a new inter-related set of research programs in the genomics of genetic variation. Second, the Center will make a substantial contribution to support of Genomics education at Penn, by providing graduate and postgraduate fellowship support. This project will address this phenomenon by systematically examining expression profiles on a genome-wide level, using microarray technology, and a relatively homogeneous collection of cell lines from the CEPH families. This project will identify sites showing polymorphism for presence/absence of integration by L1 mobile elements. These sites will then be related to the variation in gene expression level determined. This project will identify and characterize the polymorphic variation in chromosomal telomeric regions. These will also be mapped with relation to variation in expression level.